query data to barchart ใน database มีข้อมูลแต่พอมา loop array มาแสดง ข้อมูลไม่มี

$sum_query = "SELECT year(SOInvHD.DocuDate) as year, month(SOInvHD.DocuDate) as month, SUM(SOInvDT.BalanceAmnt)/1.07 as currentyear
              FROM SOInvHD LEFT JOIN SOInvDT ON SOInvDT.SOInvID=SOInvHD.SOInvID 
              LEFT JOIN EMCust ON EMCust.CustID=SOInvHD.CustID
              WHERE SOInvHD.DocuDate BETWEEN DATEADD(YEAR, -1, GETDATE()) AND GETDATE() 
              GROUP BY year(SOInvHD.DocuDate), month(SOInvHD.DocuDate)";

$stmt = $conn->prepare($sum_query);
$stmt->execute();
$rows = $stmt->fetchAll();

$data_previous = array_fill(1, 12, null);
$data_current = array_fill(1, 12, null);

foreach ($rows as $row) {
    $year = (int) $row['year'];
    $month = (int) $row['month'];
    $current_year = (int) $row['currentyear'];
    
    if ($year == date('Y') - 1) {
        $data_previous[$month] = $current_year;
    } elseif ($year == date('Y')) {
        $data_current[$month] = $current_year;
    }
}